Epazote, Wormseed, Jesuit's Tea, Mexican Tea, or Herba Sancti Mariæ (Dysphania ambrosioides, formerly Chenopodium ambrosioides) is a herb native to Central America, South America, and southern Mexico. It is an annual or short-lived perennial plant, growing to 1.2 m tall, irregularly branched, with oblong-lanceolate leaves up to 12 cm long. The flowers are small and green, produced in a branched panicle at the apex of the stem.
As well as in its native areas, it is grown in warm temperate to subtropical areas of Europe and the United States (Missouri, New England, Eastern United States), sometimes becoming an invasive weed.
The common Spanish name, epazote, is derived from Nahuatl epazōtl ().
Although it is traditionally used with black beans for flavor and its carminative properties, it is also sometimes used to flavor other traditional Mexican dishes as well: it can be used to season quesadillas and sopes (especially those containing huitlacoche), soups, mole de olla, tamales with cheese and chile, chilaquiles, eggs and potatoes and enchiladas.
Epazote essential oil contains ascaridole (up to 70%), limonene, p-cymene, and smaller amounts of numerous other monoterpenes and monoterpene derivatives (α-pinene, myrcene, terpinene, thymol, camphor and trans-isocarveol). Ascaridole (1,4-peroxido-p-menth-2-ene) is rather an uncommon constituent of spices; another plant owing much of its character to this monoterpene peroxide is boldo. Ascaridole is toxic and has a pungent, not very pleasant flavor; in pure form, it is an explosive sensitive to shock. Allegedly, ascaridole content is lower in epazote from México than in epazote grown in Europe or Asia.